What started off as a peaceful protest against government cutbacks and economic inequality has turned into rioting on the streets of Rome.
Earlier in the day on Saturday, demonstrators gathered beneath the shadow of the Colosseum to show their support for movements started by the Indignados in Spain and Americans involved in Occupy Wall Street.
However, fears about a repeat of trouble in protests last December have come true.
Tens of thousands of people had gathered in the Italian capital, which was put under a security lockdown which included the mobilisation of 1,500 police officers.
Banks had their windows smashed and vehicles were set on fire, including a police van that had officers inside it. It is believed they escaped unharmed as the crowds threw rocks.
Water canons and tear gas are being used against the violent protesters, who include gangs of young people, some wearing hoods and covering their faces.
Police say at least three people have been wounded as street fights break out.